[Free Registration/Login may be required to access all resource tools.] While a woman is pregnant, the developing baby may be called an embryo or a fetus. The embryo stage lasts until the end of the 8th week after fertilization. After...

Discover the development of an embryo. Beginning with fertilization and progressing through each stage in the first trimester and continuing every two weeks for the second and third trimesters. This site is meant for medical students and...